(a) Field of the Invention
The present disclosure relates to a composition for bleaching tooth, and more particularly, to a composition for bleaching tooth showing an excellent bleaching effect.
The present application is based on, and claims priority from Korean Patent Application No. 10-2013-0115257, filed on Sep. 27, 2013, the disclosure of which is hereby incorporated by reference herein in its entirety.
(b) Description of the Related Art
Tooth discoloration that has been known until now may be divided into intrinsic tooth discoloration caused by nerve injury inside tooth, aging, or overuse of antibiotics such as tetracycline, and extrinsic tooth discoloration caused by food or tobacco debris, coffee, black tea, etc. deposited on the outer surface of tooth.
Tooth bleaching which is performed to improve tooth discoloration includes a home bleaching method self-administered and an office bleaching method professionally administered. Compared to the home bleaching, the office bleaching uses a tooth bleaching agent containing a relatively high concentration of hydrogen peroxide and also an activation system such as heat and light in order to enhance the tooth bleaching effect. Since there is a concern about damage of the tooth nerve due to the system using heat, a system of enhancing the tooth bleaching effect by using light has been preferred.
Although the light-activated system is preferred, there are few light activators of which light catalytic activity has been proven. Further, the tooth bleaching effect of the light-activated system is still under controversy. Some studies reported that the light-activated system produced much better bleaching effects than a non-light system. However, another study reported that there was no difference between the light-activated system and the non-light system. Likewise, superiority of the light-activated system over the non-light system has not been clearly demonstrated yet.
The light activator used in the tooth bleaching agent is required to have high chemical stability as well as its light catalytic activity. The tooth bleaching agent contains a high concentration of hydrogen peroxide as a strong peroxide. Therefore, if the light activator is not chemically stable, it is oxidized before acting as a catalyst. Hydrogen peroxide is known as a material having an oxidative power strong enough to decompose a variety of industrial organic or inorganic pollutant. Compounds having hydroxyl or ketone groups may be easily decomposed or oxidized in the presence of hydrogen peroxide. Therefore, organic compounds or complexes containing organic compounds are not suitable as light catalysts of tooth bleaching agents.